Low dispersion missile and launching structure



P. C. PETRE Nov. 14, 1961 LOW DISPERSION MISSILE AND LAUNCHING STRUCTURE Filed NOV. '7, 1958 INVENTOR.

PHILIP c. PETRE BY M f ATTORNEY II/Il/lll/l/ 3,668,379 Patented Nov. 14, 1961 3,008,379 LOW DISPERSION MISSILE AND LAUN CHIN G STRUCTURE Philip C. Petre, Santa Barbara, Calif., assignor to Curtiss- Wright Corporation, a corporation of Delaware Filed Nov. 7, 1958, Ser. No. 772,473 2 Claims. (Cl. 891.7)

This invention relates generally to missiles and more particularly to an improved rocket motor and missile body construction in combination with a launcher for minimizing dispersion of the missile during its initial stages of flight.

Conventional rocket motors nearly always exhibit thrust eccentricities as a consequence of uneven or non-uniform combustion of the fuel. The result of such thrust eccentricities is dispersion of the missile. The problem of maintaining a missile on course and thus minimizing dispersion as a consequence of thrust eccentricities and misalignment can be solved to some extend by providing a relatively long launching frame which will hold the missile on a desired course during the initial stages of motor operation. Launchers of considerable length, however, are not only conspicuous and bulky but are relatively expensive.

Another solution is to rotate the entire missile so that the established gyroscopic properties will maintain the missile in a desired direction of flight notwithstanding thrust misalignments. Such rotation has the additional advantage in that any existing thrust misalignments themselves are caused to revolve about the central axis of the missile as a consequence of the rotation and will thus tend to result over unit time intervals in a fairly accurate axially aligned thrust.

The major disadvantage of rotating the entire missile body is its effect on the guidance equipment normally housed in the nose portion of the missile. In other words, it is not possible to use simple and conventional guidance equipment if the entire missile is rotating at a rapid rate because of the resulting centrifugal forces. In addition a gyroscopic platform upon which most guidance systems are vitally dependent is rendered useless if allowed to tumble which is a consequence of spinning. The problem of providing proper guidance equipment in a rotating missile body can be solved but the increased weight and complicity of such equipment necessitates sacrifices in the weight and size of the payload that the missile can carry.

Bearing the foregoing in mind, it is a primary object of the present invention to provide a novel missile and launching arrangement in which dispersion of the missile is minimized and yet the guidance equipment and other instrumented compartments of the missile are not subjected to any rotation.

Another important object is to provide a missile and launcher combination of the foregoing type which does not require an appreciably large launcher and yet in which thrust eccentricities and misalignments are substantially nullified.

Briefly, these and many other objects and advantages of this invention are attained by providing a missile body and rocket motor with means for rotatably mounting the rocket motor to the body. 'By this arrangement, only the rocket motor itself need be rotated with the subsequent advantages of uniform thrust distribution with respect to the central longitudinal axis of the missile.

In order to impart a rotation to the motor and not to the body a special launcher is provided including guide rails for engaging lugs on the missile body during its initial acceleration stages to prevent the body from rotating as the missile travels along the launcher. The rocket motor of the missile, however, is arranged to be intercoupled with suitable means on the launching frame for imparting a rotation to the motor in response to rectilinear move ment of the entire missile. In a preferred embodiment, this intercoupling may take the form of a pinion gear secured to the rocket motor for rotating the same and a stationary rack secured to the frame meshing with the pinion gear. The teeth of the gear and rack are so angulated that rectilinear motion of the missile along the rack will impart a rotation to the pinion gear and thus to the rocket motor.

An advantage of the foregoing structure resides in the fact that the energy of the rocket motor itself is employed to impart the desired rotation thereto, the guide rails serving to hold the main body portion of the missile rotationally stationary.

A better understanding of the inventionwill be had by referring to a preferred embodiment thereof as illustrated schematically in the accompanying drawings, in which:

FIGURE 1 is a schematic perspective view of the missile and launcher arrangement of this invention;

FIGURE 2 is an enlarged fragmentary view showing the portion of the misile and one guide rail enclosed in the circular arrow 2 of FIGURE 1;

FIGURE 3 is an enlarged view partly in cross section of the rear portion of the missile of FIGURE 1; and

FIGURE 4 is an enlarged view partly in cross section of the forward portion of the missile of FIGURE 1.

Referring to FIGURE 1, there is illustrated a main body portion 10 of a missile secured within a launching structure. This launching structure includes rear and front ring supports 11 and 12' between which are secured a plurality of rails 13, 14, 15, and 16. The end rings are respectively supported on suitable stands 17 and 18.

Certain portions of the missile are arranged to engage the rails to hold the missile body 10 rotationally stationary while permitting the missile to travel longitudinally along the launcher. In the particular example chosen for illustrative purposes, the extreme ends of the missile tail fins, for example, the fins 19 and 20 ride along the rails 14 and 15. One means of engaging the ends of the fins with the rails is by providing a simple slot 21 such as shown clearly in FIGURE 2 within which the rail 14- can ride. The front portion of the missile may be provided with radially projecting lugs 23 and 24 similarly coupled to the rails 14- and 15, for example, so that any rotational motion of the missile body 10 is prevented and yet the missile is free to move longitudinally forwardly and out of the launching frame.

The missile includes a rocket motor 25 shown positioned internally within the missile and provided at its rear end with a pinion gear 26. The launcher in turn is provided with a rack 27, positioned to mesh with the pinion gear. Referring particularly to FIGURE 3, it will be noted that the rear portion of the rocket motor 25 is mounted for rotation within the missile body 10 by ball bearings 28. The pinion gear 26 itself includes teeth 29 angulated with respect to teeth 30 of the rack 27 so that rectilinear motion of the entire missile in the direction of the rack will impart a rotation to the pinion gear 26 and thus rotate the motor 25 within the main missile body 10. In FIGURE 4, the front portion of the rocket motor 25 is rotatably supported to the missile body by a front bearing 31.

From the foregoing, it will be evident that when the rocket motor is fired the developed thrust will accelerate the missile body 10 along the launching frame. This movement will impart a rotational movement to the pinion gear 26 in turn rotating the entire motor 25 within the body to the end that thust misalignments are essentially cancelled out with respect to the central longitudinal axis of the missile. The missile body on the other hand will the dmirable effects of minimizing dispersion are maintained. The missile body will have convntionalroll control which will prevent spinning of the body after leaving from the launcher. V 1

While only one particular embodiment of the invention has been disclosed, it will be clear to those skilled in the art that other equivalent means can be employed for imparting a rotation to the rocket motor 25. An important feature of the invention resides in the fact that the energy of the engine itself is employed for imparting this rotation so that the entire structure is relatively simple. Since modifications that fall clearly within the scope and spirit of the invention will readily occur to those skilled in the art, the improved low dispersion missile and launching structure is not to be thought of as limited to the particular embodiment set forth for illustrative i .4 1 for guiding said body in a straight line path while preventing rotation of said body; a gear carried by said rocket motor and coupled to rotate said rocket motor; and a rack secured to said launching structurein meshing engage ment with said gear, the teeth of said gear and rack being angulated with respect tosaid straight line path so'that' movement of said gear alongsaid rack as a consequence of thrust developedby said rocket motor imparts motion to said gear to rotate said rocket motor relative to said body while said missile I is movedalong said guide means.

cluding lug portions adapted to ride along said rails.

References Cited in the fileof this patent 1 UNITED STATES PATIENTS g I 1,602,037 Mixsell Oct. 5, 1926 r 2,623,465- Jasse Dec. 30, 1952 2,818,779 Koeper Ian. 7, 1958 2,849,955 Smathers V Sept. 2, 1958 2,900,873 Wust f Aug. 25; 1959 V 'TQ EIGN PATENTS Y 1 89,970 Sweden V Aug. 10, 1931 7 1 7 

